SOLEPHEM(3)



NAME

     solephem -- calculates various astronomical  quantities  for
     the sun


SYNOPSIS

     solephem(time,ephem)
     TIME time;
     double ephem[19];


DESCRIPTION

     This procedure finds the ephemerides for the sun at the time
     "time."  Several quantities are computed and returned in the
     array  ephem.   See  the  American  Ephemeris  and  Nautical
     Almanac  and  program  comments for details of methods used.
     Quantites computed:

       ephem[ 1]: time used for computation
       ephem[ 2]: t=time in centuries of 36525 days since 1900.0
       ephem[ 3]: jd = Julian date
       ephem[ 4]: st = Siderial time (within day)
       ephem[ 5]: ra = right ascension (geometric)
       ephem[ 6]: dec= declination (geometric)
       ephem[ 7]: clong = geometric longitude
       ephem[ 8]: l0=Carrington Longitude of disk central point
       ephem[ 9]: b0 = latitude of central point of disk
       ephem[10]:  p=position  angle  of  northern  extremity  of
                   rotation axis -- to east from north in sky
       ephem[11]: r = true distance to sun in AU
       ephem[12]:   rsun=true   semi-diameter   of   sun(arc-sec)
                   uncorrected for irradiance (d.f. AENA pg.541)
       ephem[13]: vearth=angular velocity of earth * 1AU (m/s)
       ephem[14]: eot = equation of time
       ephem[15]: b0 wobble (m/s)
       ephem[16]: phi = aux angle for deltav
       ephem[17]: sin(p)
       ephem[18]: cos(p)


FILES

     /usr/local/lib/libastro.a        ( -lastro )
     /usr/src/local/astro/solephem.c


SEE ALSO

     date (on local)


DIAGNOSTICS

     none or obvious


BUGS

     Note that because of the AENA formulae  used,  some  of  the
     numbers do not make sense if a time before the middle of the
     20th century is given.